oolin constraints now are rendered into linear ones, provided all inputs of the oolin involved are oovar instances

Contributors:

Thanks to Stepan Hlushak for writing GLP solver de (based on differential evolution)

Backward incompatibilities:

if you provide derivatives for constraints, then for each constraint c_i or h_j: R^n -> R^s_k you should provide dc_i or dh_j with exactly same number of outputs, i.e. R^n -> R^(s_k, n), otherwise correct solution is not guaranteed (for named variables syntax you shouldn't care of the issue, each oofun has single function for obtaining output and no more than a single user-provided function for obtaining output derivatives).